I did it as 11 man (won with seconds to spare) like 2 days before the cap got raised from 75, so I'd say a single party at 90 would have a simular experience.

I wouldnt say you need any particular strat (its just like any other boss fight) but heres a few pointers you -need- to make sure on, espesh as a low man group.

1: Stun Dissipation. Seriously that is a make or break move. Till 20% it does it near every 20% (just under if i recall correctly) so its easy to have the BLM and/or RDM/BLM ready for this.

2: Double erase all status moves. Im assuming you will be using one tank so that should be a lil easier.

3: Any DD run in n WS, then run out, a SAM/THF would be nice here. I found MNKs are awesome too in full Subtle Blow gear, they can also double up as a extra stunner.

4: Have a mage or 2 make a "hate" macro, as in, /assist Proto-Ultima to see who he will draw in once the Citadel Buster countdowns start under 20%. Its just useful to know who is in the firing line and who isnt, so the others can GTFO up the ramp and out the door. With luck it will be your tank, just hope his/her hp is good and has a good MDT set.

5: Slow and Steady. This is a big one imho, do not rush this, 60 minutes is enough to get this done. Rushing leads to mistakes. Allow your tank to get some hate before any nukers go nukey. Its nice to have a big nuke near each 20% to force the dissipation though.

As regards set up for a low man, I really cannot say. Id personally go for Tank (job of choice, so im guessing a tank geared MNK, though PLD was fine "back in the day", -30% MDT goes a long way =p), WHM/BLM, BRD with either whm or blm sub, BLM/RDM, then 2 DD of choice. BRD can be substituted with RDM here, but I'd say the songs would be better overall.

This is just from my experience from running a shell for 1 year, back at 75, where we would usually do bosses with no more than 13 people. We never had a single loss and was blessed with regularly good drops and to this day I am proud of that and my members of the time. Yes I know it was prob able to be done with less, espech Omega, but it allowed for faster kills and so. I'm sure there are many people that can offer as good and better advice. :)

We killed this with 5 a couple months ago. Sam Sam War Whm Blm I believe. Died maybe in 5 minutes or so. As long as your whm knows how to cure and blm knows how/what to stun, everything should be fine.

If you use Raz's strat you could also take a SMN for Perfect Defense at 20% to zerg him down. SMN Also does a fair job at DD on this guy cause hate is wiped after release and the avatar is the only thing in AoE range. Can also help with Cures/Status Removing (Leviathin) and put out a DD BP with the same pet. So it wouldn't be a waste of a spot.

We did him at 90 and he can still be a little hairy, but if you have some seasoned stunners/healers on him he can be cake. If not, you might as well save your pop set. GL~

Thanks for the strats.
Another favor id like to ask is since we re note a Shell that burns Jobs in aby (statement, not judgement) im not sure about having Jobs For that.

We would be 7 on thr fight, could someone pls (checkin available Jobs on LS page on ffxiah) suggest what we should do?
I m not entirely against letting others in The fight, but it would be a small but precious achievement if we could do The fight ourselves. Just explaining why im asking that kind/amount of help, we rarely do some "events" and would be really annoying to fail and get The popset again.

We killed this with 5 a couple months ago. Sam Sam War Whm Blm I believe. Died maybe in 5 minutes or so. As long as your whm knows how to cure and blm knows how/what to stun, everything should be fine.

To answer your question, I would say you could Full Attack if the stunner was on his Stun Macro. Citadel Buster is a pain. But you want to give Stun enough to cool down inbetween Citadel Buster's. He uses it at 79%, 59%, 39% and 19%. Or 80/60/40/20 oen of the two (check the wiki). So you don't want to push P/U from % to % too fast, you atleast want stun to be up. Or have two stunners alternate. @20% you definately want to zerg him though. Best of luck.